In recent years, due to the development of digital equipment such as computer, the operation data to deal with and the throughput of two-dimensional and three-dimensional image data have become enormous. In order to quickly process such information, a large-volume, high-speed memory and a high-performance microprocessor have become necessary. Furthermore, it is expected that a trend to broadband will be accelerated and that the processing capacity required of digital equipment will increase more and more, along with the development of network such as the Internet.
In order to accomplish this demand, many of device equipment, which are represented by semiconductor devices, are required to achieve further densification and integration. In particular, the demand for photolithography technique, which makes a fine processing possible, has become stricter year by year. For producing a DRAM having a degree of integration of 1G bits or greater, it is necessary to have a processing technique of the minimum line width of 0.13 micrometers or less. In response to that, the utilization of a photolithography using ArF excimer laser (193 nm) has started. Furthermore, the development of photolithography using F2 (157 nm) is going on for the purpose of forming fine patterns.
In these wavelength regions, novolac and polyvinyl phenol series resins, which have conventionally been used for resist materials, are too high in light absorption. Therefore, it is not possible to use them. Therefore, acrylic resins (see Patent Publication 1) and cycloolefin resins (see Patent Publication 2) have been examined. However, resins that are highly transparent at a wavelength of F2 (157 nm) are very limited, and therefore advantage of fluororesins has become clear. In particular, there have been reports that fluorine-containing resist resins containing hydroxyl group have a characteristic that is also superior in hydrophilicity, and therefore they are expected very much (Non-patent Publications 1 and 2).
The introduction of fluorine atom improves transparency in ultraviolet region, but at the same time it lowers etching resistance. In connection with polymerizability too, there remained many problems that monomers, in which fluorine atom and trifluoromethyl group are directly bonded to conventional norbornene rings, are low in polymerizability to lead to low yield and are not capable of providing sufficient molecular weights as materials. Therefore, functions that are achievable by these existing compounds are not necessarily sufficient. There has been a desire for a novel monomer or its raw material that is capable of efficiently providing a further superior polymer.
On the other hand, epoxy resin and the like are used in the field of semiconductor device package, but there is used a method in which fine particles of silicon oxide (SiO2) having a thermal expansion coefficient close to that of a device substrate (Si substrate) are added to a sealing resin material for the purpose of reducing thermal stress upon mounting onto a printed wiring board. However, in conventional technique, a plastic package of conventional structure using epoxy resin inferior to metal, ceramics, etc. in thermal conductivity is inferior in radiation characteristic and is quite high in thermal resistance. Therefore, it was disadvantageous in terms of a long-term reliability as an IC of high electric-power consumption such as power IC or as a package of IC operating at high speed. Furthermore, fine particles of SiO2 added to resin to make it have low stress are very hard. Therefore, thermal stress generated upon mounting onto printed wiring board has added a large pressure locally to the device surface, thereby generating device destruction. In other words, there has been a demand for a material that is high in heat resistance and hardly adds thermal stress to the device surface in the field of semiconductor package (see Patent Publication 3). In fact, it is difficult to satisfy the demanded performances by a single semiconductor package material. Thus, various protecting films, etc. are used together. We can say that the package material and the protecting film are integrated and achieve their functions by compensating their respective weaknesses. A passivation film is used for preventing the intrusion of water and impurities into semiconductor chip, and a buffer coating film is used for loosening stress concentration occurring in a package material. Hitherto, inorganic compounds such as silicon oxide have primarily been used for thin film materials, such as insulating film and protecting film, used for semiconductors. Nowadays, however, the usefulness of heat resistant polymer materials such as polyimide have been recognized, and they are used for layer insulation film, passivation film, buffer coating film, etc. For the request of integration and high-speed of semiconductors in recent years, there is a demand for a material corresponding to the high-speed transmission of signals. In high-speed transmission, the propagation delay of signals becomes problematic, but it is effective to make a material have a lower dielectric constant since the propagation delay is proportional to relative dielectric constant of a material. Nowadays, it is known that fluororesins are low in dielectric constant, and fluorine-containing polyimide is also investigated as one of potential materials. A resin, into which fluorine atom has been introduced, has special properties possessed by fluorine, such as water repellency, non-adhesiveness, etc., and sometimes it can be utilized for the aimed use. Sometimes, however, its utilization was difficult due to its specificity. Along with the appearance of new semiconductor applied products in recent years, semiconductor packages have also been diversified. There have been various demands for them to be more compact, thinner, lower in dielectric constant, etc. A package material satisfying these has been demanded.
Patent Publication 1: Japanese Patent Laid-open Publication 10-161313
Patent Publication 2: Japanese Patent Laid-open Publication 2000-89463
Patent Publication 3: Japanese Patent Laid-open Publication 8-241913
Non-patent Publication 1: H. Ito, H. D. Truong, et al, J. Photopolym. Sci. Technol., 16, 523-536 (2003)
Non-patent Publication 2: Francis Houlihan, Andrew Romano, Ralph R, Dammel, et al, J. Photopolym. Sci. Technol., 16, 581-590 (2003)